As a method of washing clothes made from wool for example, a washing method called dry cleaning has widely been known. The dry cleaning is a method of cleaning clothes using a petroleum solvent or an organic solvent as a cleaning liquid. The dry cleaning is the washing method capable of preventing loss of shapes shrinkage, swelling, and the like of the clothes while washing clothes conveniently. This is one of reasons of the widespread of the dry cleaning.
More specifically, contaminations adhering to clothes are usually of water-soluble contaminations such as sweat, foods, and mud. In order to perfectly clean such water-soluble contaminations, it is necessary to wash the clothes with water. However, when clothes made from wool are washed with water, scales formed on a surface of fibers (wool) are damaged to change a fabric to a felt-like one. When the fabric becomes feltish, the clothes are hardened to loose the original texture and to be difficult to wear. However, when a petroleum solvent or the like is used as the cleaning liquid, the above-described fabric change does not occur. Therefore, the dry cleaning has widely been employed as a clothes-washing method.
However, in a case where the petroleum solvent is used as the cleaning liquid, the water-soluble contaminations adhering to the clothes are not cleaned perfectly, and yellowing and the like of the clothes can occur later on. That is, the dry cleaning is employed for the purpose of avoiding the risk of damage on clothes even when it is necessary to wash the clothes with water in order to perfectly clean the contaminations of the clothes.
Washing methods employed for conventional washing apparatuses can be divided into two types. One of them is a washing method utilizing a rotating current of a washing liquid (see, for example, Patent Publication 1), and the other is a washing method utilizing a mechanical force (see, for example, Patent Publications 2 and 3).
With the washing method utilizing the rotating current of the cleaning liquid, a washing tub is rotated about a rotation shaft disposed in a substantially vertical direction. In such a washing tub, the cleaning liquid is rotated in a substantially horizontal direction. Clothes are cleaned by means of the rotating current of the cleaning liquid. On the other hand, with the washing method utilizing the mechanical force, a washing tub is rotated about a rotation shaft disposed in a substantially horizontal direction. In such a washing tub, clothes placed therein are moved upward along an inner wall surface of the washing tub and then fall down. The clothes are cleaned by means of impact caused when the clothes fall on the inner wall surface of the washing tub. That is, with the washing method utilizing the rotating current of the cleaning liquid, the contaminations are separated when the clothes are twisted round by means of the rotating cleaning liquid. On the other hand, with the washing method utilizing the mechanical force, the contaminations are separated by means of the impact applied on the clothes. In both washing methods, burden on the fabrics is large, and, though a certain cleaning effect is achieved by the washing methods, the fabrics are steadily damaged.
Conventional washing apparatuses and washing methods are disclosed in Patent Publications 1 to 12 listed below. Particularly, Patent Publication 4 (JP-A-4-61893) discloses a washing method for flipping a laundry article by means of a jet current and a washing machine for performing the washing method. As disclosed in Patent Publication 4, the washing machine is provided with an outer barrel (1) and an inner barrel (4). The laundry article is placed in the inner barrel (4), and the outer barrel (1) is filled with a washing liquid. A propelling wing (18) is disposed in a space communicated with an interior of the outer barrel (1). When the propelling wing (18) is rotated, a strong swirling current of the washing liquid is generated in the outer barrel (1). The laundry article is twisted round by the swirl of the washing liquid, so that the contaminations are cleaned.    Patent Publication 1: JP-A-2002-58892    Patent Publication 2: JP-A-2003-260290    Patent Publication 3: JP-A-2001-269495    Patent Publication 4: JP-A-4-61893    Patent Publication 5: JP-A-4-164494    Patent Publication 6: JP-A-9-248395    Patent Publication 7: JP-A-9-276582    Patent Publication 8: JP-A-6-238086    Patent Publication 9: JP-A-11-169579    Patent Publication 10: JP-A-60-246790    Patent Publication 11: JP-UM-B-35-31858    Patent Publication 12: JP-A-11-267391